I’m considering adding WooCommerce support in future themes….but as you said, woo commerce is a lot more robust and best for large e-commerce sites. You didn’t mention what you are selling, but you might want to check out PayPal based plugins. Also, check out http://trinitronic.com/downloads/#wordpress-downloads
I use one of their plugins for my individual theme purchase to download function, although mine is for Joomla which is what my site here is using, but have been using them for a couple years now.